Compressed air supply system



Jan. 19, 1954 ALEXANDER 2,666,568

COMPRE$SED AIR SUPPLY SYSTEM Filed NOV. 29 1950 518.1 1\

INVENTOR. 12

KmzeihA Alexander A 7' TOPNE Y -A -AH i atented jan. 19, 1 t it COMPRESSED AIR SUPPLY SYSTEM Kenneth A. Alexander, Forest Hills, Pa., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania Application November 29, 1950, Serial No. 198,065

2 Claims.

This invention relates to a compressed air supply system and more particularly to a compressed air supply system comprisingnovel means for storing and removing moisture from the *compressed air.

A prime object of the invention is to provide a small, compact portable unit for compressing air including means for storing the compressed air and removing the moisture from same.

Other objects and advantages will become apparent from the following more detailed description of the invention taken in connection with th accompanying drawing in which:

Fig. 1 is an elevation view in outline of a commercial form of air compressing apparatus embodying the invention; and i Fig. 2 is a schematic representation, of the same apparatus, partly in outline and partly in section.

Description Referring to Figs. 1 and 2, the air compressing apparatus comprises an air compressor device i driven byan electric motor 2 via such as a V-belt 3. An aftercooler 4, in the form of continuous coils 5 of copper tubing for example, is connected to the compressor device I to receive the disunder pressure, to a safety valve device I6 and t, to a pressure switch device I! via a pipe I 8.

The safety valve It may be of any well-known type, as for example it may comprise a spring loaded valve -i6a which will unseat should the pressure of the compressed air acting on said valve become excessive.

ii. rod 26 is attached to the piston 20 for reciprocable movement therewith. The rod 26 extends through the spring'ohamber 23 and out- *1 wardly through an accommodating openin in charge of the warm compressed air therefrom.

Circulation of the warm discharged compressed air will be cooled in the usual manner in passing through the aftercooler coils and in thus being cooled, will lose much of its moisture in the form of condensate which collects on the inner walls of the coils. 1 v

' According to ,a feature of the invention, the continuous aftercooler coils 5 are disposed around a vertical axis with the discharge of compressed the casing. The outermost projecting end of the rod 25 carries aswitch plate 28 of electrical conducting material attached to the rod via nonconducting material 30. Two spaced apart electrical contact elements 32 and are fixed in the path of travel of the switch plate 28. 7 One contact element 34 is connected via a wire 35 to one motor terminal 36, the opposite terminal 3'! of which motor may be connected to ground via a 6-,. wire 38. The other contact element 32 may be air from the compressor entering from the top w and leaving at the bottom via such as a delivery pipe 6 connected thereto by means'of'a coupling 1. By virtue of the vertical arrangement of the aftercooler 4, condensate condensing on the inner walls of the coils 5 will flow tov the bottom. For collecting such condensate at the bottom of the aftercooler 4 an additional collecting coil 8 is added to the aftercooler in substantial sym metry with the coils 5. The coil 8 joins the bot tom of the lowermost end of the continuous coils 5 preferably at a point preceding the coupling 1 to assure that condensate will drop into the condensate collecting coil 8 rather than continue into the delivery pipe 6. A two-way cock 9 is connected to the lowermost discharge end of the collecting coil 8, which cock in the position in which it is shown in the drawing connects said discharge end to a blowdown valve device It] via a pipe II,

or in another position, will connect said discharge end directly to the atmosphere via a port I2.

The aftercooler coils 5 also act as a small volume reservoir for storingfthe compressed'air from the compressor I and the delivery pipe 6 is connected to a four way union fitting I4 which also connects to a supply pipe.,I5 for connection to adevice or devices" (notshown) to utilize fluid connected via a wire in to one pole of a battery H, the opposite pole of which battery may be grounded via a wire 42.

When the pressure of the compressed air in coils 5 and pipe I8 drops to a chosen low value, such pressure as felt in chamber 2| in the pressure switch device I'I will allow the spring 22 to move the piston 2i! in the direction of said chamber until the switch plate 28 engages the contact elements 32 and 3a to complete electrical circuit to the motor 2 for'operating same and thereby running the compressor I to bring the pressure of the compressed air up to a desired value. When such a desired value is shortly reached, this increased pressure of compressed air as felt in chamber 2! will cause movement or the piston 29 in the direction of chamber 23, and through resultant movement of rod 26, will unseat the switch plate 23 from contact elements 32 and 3% to interrupt the electrical circuit to the motor 2, stopping same nd thereby stopping the compressor I.

The blowdown valve device I0, schematically, may comprise a casing 50 having an inlet chamber 5i connected to'the pipe I I and an exhaust chamber 52 open to atmospherevia ports 57 and 3 4 53 rc i g op o ends or the on 4 1 P9,... m tryrta ther rcoo er.eoilsisgrarc mp oye accomni 54 and. r i ti ridensajtej'and which "comprises and 55 are connected one to the Ether y imp *ov'fmeans 'for automatic blowout of such a stem 60 extending with clearance through. condensate with use of only a small amount of opening 56. The length of the stem 50 relative cam ress ai to the length of Opening 55 is thafbfiflf Having? new described my invention, what I valves may not be closed atany one time, claim ashew and, desire to secure by Letters Patspring Si in chamber 5| is arrange valves 54 and 55 toward seated and sitions, respectively. A stem 52; attached to (and 55 extends through chamber 52' and on (11 'pe coils arranged side by side transthe casing 50 to act as a medium wher v elyof said base plate adjacent one end thereattached valves 4, 55 iay be actuated simultaof, said pipe coils being arranged in form of a noirsly, helix"with"its' aX'is "vertical-"to permit gravity According to another feature oi the invention, 15 drainage or condensate in the coils and with the the stems: is arranged to be actuated by the uppermost end of said coils open to the discharge pressure switch deviceftl to allow-thecondensate of said compressor; a motor for'operating saidoollected in con 8 momentarily'to' be blown out'to compressor mounted On said plate adjacent the atmosphere each time thecoinpressoii 'l start-1' opposite 'end'theror; apipe fitting connected to 1. A ciompressedvair supply system comprising .pla r compressor and a continuous ed or stopped. said coilsdntermediate 'theupper'inost end and ord ng to the above feature a rigid antuatthe lowermost endthereof for conne'ction "with ing element" is attached to th'e' ifo'd 2 5 of'de'vice a compressed air using device or the'lik'e; '3 mo H'for reciprocablemovement' thfevqith tor control device connected "to"rec'eive "cemelement to is' arranged t6 extend transv rsely pressed'air'irbm said coils via said pi fitting from the rod intoabutting contact with the 2 for starting and'stoppingsaid'coinpressor in re stern 82 of device l5. By Ylltuc of "Such a'rra'ng; sponse to chosen lowanol high pre'ssuresof such m nt. as t 'r' moves q t fi n job n air, bl'ow oit'devifce cbnneetedt the lowermost of theeomnresser d e I y te up e e' end er's'aideon's w'reeiveceiidensate accumu electrical circuit to mottlatheaematine ale: lated therein, and mea'risoperative"bysaid'ijbfi;

ment 'fll'r'iarried bystem 2'6 willconscuti'vely trot dviceiri startingbi stopping "Sara motor to seat and seat valves i 5 es e t ly actuate saia'mew sir device to opii and'then After valve 54 has been unseated and va ve' close a communication" between said coil and is yet to be seated, chamber 5l' is'oben't f t fi atmosphere. A cha ber 52 a, op 50 t t th' 9 LAir com ressing ap aratus comprising an pressed air in'the"af-teriioole1 cones will cause jtfi i gn' -g jgc n e sa e el 't d ath st tel "'dorhpr rl coil 8' to be blown out da i es l ie ve nddises'tab device a, pipe '1 I, chamber 5|", said opening 1 source and chamber 52 and'po ts 5 $1,153?!- b w' wn 0 co"t'nuou's aftercooler condensate istempor ary as terminated by 'sub 1r fi na g d h isequent closure or the valve 55 and winner; allow presses an discharged such release of compressed air from the coils i5 flfl i f p 'jb fi nd f 'f as willmaterially reduce the pressure of e ergies p ssfe "air, said aftercooler m' er in- 2 1 5 ei arra e abou vernal-axis, aban- When the rod 25 of switch device 14 moves it; densatecbllcting"coil' conne cted to the lower: the direction to cause operation of the mm presso r device I by establishing 'electificalci hit to the motor 2, the actuating lementlfin niov' me with said'rod'26' win allow the pring at in device ID to consecutively unseatand 's'e'a't'v'alves 60 and 54, respectively; agai'ndurinjg" the -tirfi that both vaiv es'are unseatesd arid prior to" seat} ing of the valve 54,"cornpressed fair fromtlie aitercooler coils 5 will blow out'the condensate collected. in the collecting coil 8 via thwarts device 9, pipe H, and in device I0, thehhat'nber 5|, opening 56, chamber 52 and pofts"5'l. Su'b quent closure of "the valve 54 liinitsthe amount of compressed air from coils 5 utilized'fof such condensate blowout to'a very small amount In Fig. 1, 55 designates a base'plate 'pofiwhlch the motor 2 and compressor T are in nte' d at opposite cnqs'with the coils 5 and fat one 'd of the compressor and all other er the amp paratus between said motor'and's and coils, thereby-providing a very s me 15 able arrangement.

Resistance? Gites in t e file m th s patent It will now be seen that I'have pro ided air 7 V I D Q FE$ ATF flempressine e 'e wh c it tf'sefliembe Date ticu-larly in that the aftercpoler c oilsof itubiflg 1", 6 Q,'2 are used as a volume reservoir fofistori n he co pressed air and 11; that the low or we e h 99f 1 

